Membrane modules design

Fane, A.G., Chang, S. and Chardon, E. (2002) Submerged hollow fibre membrane module - design options and operational considerations. Desalination, 146, 231-236. 

Referring to the membrane module design, it has a big influence on the membrane-contactor efficiency, because it affects the pressure drops of the streams (and, thus, the operating pressures and flowrates), and their fluidodynamic (which means the mass and heat transport resistances of the phases). Furthermore, for hollow-fiber modules it is essential to ensure a uniform packing, in order to have... 

FIGURE 5 Membrane module design, (a) Spiral-wound (Koch Membrane Systems) (b) hollow-fiber (Du Pont) (c) tubular (generic) (d) plate-and-frame (c) pleated cartridge (Millipore). [Figure 2(d) from Strathmann and Chmiel (1985)]. 

Brewster ME, Chung KY, and Belfort G, Dean vortices with wall flux in a curved channel membrane system, 1. A new approach to membrane module design, J. Membr. Sci. 1993 81 127-137. 

Mallubhotla, H. Nunes, E. Belfort, C. Microfiltration of yeast suspensions with self-cleaning spiral vortices possibilities for a new membrane module design. Biotechnol. Bioeng. 1995, 48, 375. 

Ophoff, J. Voss, G.S. Racz, I.G. Reith, T. Systematic approach of membrane module design based on hydrodynamics. The helically twisted tubular membrane module. Proceedings of ICOM 96, Yokohama, 1996. 

Ghogomu, J.N. Guigui, C. Roucha, J.C. Clifton, M.J. Aptel, P. Hollow-fibre membrane module design comparison of different curved geometries with Dean vortices. J. Membr. Sci. 2001, 181, 71-80. 

Mass transfer in the feed and strip solutions is limited by the extent of concentration polarization. On the feed side of the membrane, concentration polarization refers to an increase in the concentration of solutes at and near the feed-membrane interface because of evaporation of water into the membrane pores (Fig. 1). The resulting solute concentration gradient between the membrane-feed interface, where the concentration is greatest, and the bulk solution induces diffusive transport of rejected solutes back through the concentration polarization boundary layer into the bulk stream. Bulk solution is simultaneously transported to the membrane wall by convection. When equilibrium has been established under a given set of operating conditions (stream flow rate, temperature, fluid dynamics imposed by membrane module design), the rate of back diffusion is equal to the rate at which the solutes are carried to the membrane surface by convective flow. ... 

Microfiltration membranes are similar to UF membranes but have larger pores. Microfiltration membranes are used to separate particles in the range of 0.02-10 pm from liquid or gas streams. Commercial MF membranes are made from a wide variety of materials including polymers, metals, and ceramics. A wide variety of membrane module designs are available including tubular, spiral wound, pleated sheet, hollow fiber, and flat sheet designs. Some modules are best suited for crossflow filtration, and others are designed for dead-end filtration. In dead-end filtration, the feed liquid flows normal to the surface of the membrane, and retained particles build up with time as a cake layer on the membrane surface or within the pores of the membrane. 

Material science aspects of synthetic polymeric membranes are presented In this survey. The objective Is to place each of the subsequent chapters of this volume Into proper perspective. Therefore, frequent reference Is made to the accompanying chapters and, where necessary, to alternative Information sources. By way of Introduction, this chapter considers In turn material selection, material characterization and evaluation, membrane preparation, membrane characterization and membrane evaluation. Membrane module design and manufacture, transport phenomena and process performance are Introduced In the discussion only as they pertain to membrane materials science. Following this Introduction, the various chapters of this volume are previewed. 

Membrane science can arbitrarily be divided Into seven Intimately related categories material selection, material characterization and evaluation, membrane preparation, membrane characterization and evaluation, transport phenomena, membrane module design and process performance. This chapter and those to follow emphasize the materials science aspects of synthetic polymeric membranes that Is, the selection, characterization and evaluation of membrane materials as well as the preparation, characterization and evaluation of membranes. Transport phenomena, membrane module design and process performance enter the discussion only as these topics pertain to materials science. 

Evaluate the ITM Syngas/ITM H2 processes using PDU data Conduct long-term stability tests of tubular membranes and seals at high pressure Demonstrate performance of pilot-scale membrane modules in PDU Complete membrane module design and select catalysts for the SEP Commission the ceramic Production Development Facility and fabricate SEP membranes Design and fabricate the SEP reactor... 

This chapter will address the special considerations that apply to incorporating dense, hydrogen-permeable metal membranes into practical membrane modules for commercial and industrial use. It is organized to present a brief historical overview, a general review of hydrogen-permeable metal membranes, scale-up from laboratory test-and-evaluation membrane modules to commercial membrane modules, membrane module design and construction, and commercial applicability. 

Regardless of the membrane module design, effective performance is dependent on rapid mass transfer at the feed side of the membrane. There are several comprehensive references on mass transfer [10], so it will not be addressed in detail here. However, one should consider mass transfer because it affects two design issues the manifolding of the feed stream to each membrane, and the feed channel design and dimensions. The detailed analysis of these issues differs somewhat when one considers stacked planar modules and tubular modules, but the fundamental objectives are quite similar. 

The membrane is in the form of a hollow fiber (see Fig. 109), which has the advantage of reduced outer dimensions together with a large membrane area. The membrane module consists only of the hollow fiber bundle and the module housing. Such a simple structure can avoid difficulties encountered with other membrane module designs, such as sealing of flat seat type and spiral-wound type membranes and furthermore can reduce not only the volume and the weight of the modules, but also the total system size. 

In general, membrane science research can be divided into seven major areas, that is, material selection, material characterization, membrane fabrication, membrane characterization and evaluation, transport phenomena, membrane module design, and process performance. Among these areas, materials chosen for membrane fabrication are the most important part in the membrane technology and this phenomenon can be reflected by the significant amount of technical articles published in the literature. 

The specifications of the prototype cross-flow membrane module designed according to [113] are as follows membrane area, 5.0 m nominal pore size, 0.3 mm fiber material PP (Accurel Q3/2) and fiber diameter (inside/out-side), 0.6/1.0 mm. A feasibility study has demonstrated that CO2 can be produced economically from flue gas on a large scale [103]. The economic analysis carried out in the study indicates that, at a production capacity of 10 tonnes of CO2 per hour, production costs will be around US 50 per tonne of CO2. At this cost level, the process is cheaper than, for example, CO2 delivered by truck or current CO2 production processes. 

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